4.0

M4.0 Earthquake 23 km NW of Finschhafen, Papua New Guinea — March 19, 2021

2021-03-19 19:08:19 UTC (2021-03-19) · approx. 5:08 AM UTC+10 local

MagnitudeM4.0(mb)
Time19:08 UTC≈ 5:08 AM UTC+10
Depth58.1 kmshallow crustal
Coordinates-6.422°, 147.683°
Felt byNo felt reports
Status✓ Reviewed by USGS

On March 19, 2021 at 19:08 UTC, a magnitude 4.0 shallow crustal earthquake struck 23 km NW of Finschhafen, Papua New Guinea, at a depth of 58.1 km and coordinates -6.4223°, 147.6834°.

Physical scale: An earthquake of magnitude 4.0 releases seismic energy equivalent to roughly 15 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 347 m — a useful intuition for the size of the slip patch on the fault.

This earthquake is part of an ongoing aftershock sequence following the magnitude 5.3 mainshock that occurred 5 days ago 72 km NW of Finschhafen, Papua New Guinea. Since the mainshock, the USGS has recorded 0 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.

Map showing earthquake epicenter at -6.42°, 147.68°

Earthquake Details

Magnitude
4.0 mb
Depth
58.1 km
shallow crustal
Location
-6.4223°N
147.6834°E

Technical Information

Event ID
us6000dwq2
Event Type
earthquake
Status
✓ Reviewed
Significance
246
Azimuthal Gap
106.0°
Min Station Distance
3.008°
RMS Residual
0.74 sec
Last Updated
2021-06-02 15:22:59 UTC

Common Questions

How strong was the magnitude 4.0 earthquake near Finschhafen, Papua New Guinea?

The magnitude 4.0 earthquake that struck 23 km NW of Finschhafen, Papua New Guinea on March 19, 2021 at 19:08 UTC had a depth of 58.1 km. For context, this was a light earthquake commonly felt near the epicenter.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.0 earthquakes can continue for several days and gradually diminish over time.

Is this the same earthquake as the M5.3 one earlier?

No. This magnitude 4.0 earthquake is an aftershock of the larger magnitude 5.3 mainshock that occurred earlier 72 km NW of Finschhafen, Papua New Guinea. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.

Understanding This Data

Magnitude 4.0 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us6000dwq2). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, March 19, 2021). M4.0 Earthquake 23 km NW of Finschhafen, Papua New Guinea — March 19, 2021. Retrieved June 2, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000dwq2/